ArrayFire published some GPU benchmarks on a collection of ArrayFire functions.
See the results here: ArrayFire Benchmarks: AMD Kaveri vs Intel Haswell Part-1 | ArrayFire
(Hint: The AMD processor did very well.)
If you're curious what ArrayFire is, we most recently blogged about ArrayFire here: http://developer.amd.com/community/blog/2014/11/21/arrayfire-now-open-source/
And you can get the open source code here: Download | ArrayFire